ISDN BRI Connection problem

Unanswered Question
Aug 14th, 2007

Hi Experts,

I have a problem here,not too sure if it is the BRI Card problem. WHen I do a shut and un-shut on the card, the state will go to MULTIFRAME_ESTABLISHED from TEI_ASSIGNED when doing show isdn status.

Is this due to the card problem?

Thanks in advanced.

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Overall Rating: 2 (2 ratings)
Paolo Bevilacqua Tue, 08/14/2007 - 00:56

multiframe_established is also a valid state for BRi interfaces. Does calls work? Whta do you see with debug isdn q921 and debug isdn q931 ?

Richard Burts Tue, 08/14/2007 - 01:56


In addition to what Paolo has answered I would say that not only is multiframe_established a valid state, but it is a more desired state than TEI assigned.

In addition to his question about a921 and q931 I would ask you to post the output of show isdn status.

What you have described so far is well within the range of normal and does not show anything that indicates a problem.



dany.datacraft Tue, 08/21/2007 - 21:45


I think I have the same problem as Cindy. Here are some additional information:

1. After 3 minutes of idle (no calls), the isdn status goes back to TEI_ASSIGNED (Layer 1 is active):

SGTSCR01#sh isdn status

Global ISDN Switchtype = basic-net3

ISDN BRI0/1/0 interface

dsl 2, interface ISDN Switchtype = basic-net3

Layer 1 Status:


Layer 2 Status:

TEI = 101, Ces = 1, SAPI = 0, State = TEI_ASSIGNED

Layer 3 Status:

0 Active Layer 3 Call(s)

Active dsl 2 CCBs = 0

The Free Channel Mask: 0x80000003

Total Allocated ISDN CCBs = 0

2. At this state, we are unable to make any isdn call (using isdn test call command).

3. If we do a shut/no shut, the isdn status goes back to MULTIPLE_FRAME_ESTABLISHED and we are able to make isdn call

4. Debug output when the isdn status change to TEI_ASSIGNED is as follows:

Aug 21 07:10:51.260 gmt: ISDN BR0/1/0 Q921: User RX <- RRp sapi=0 tei=101 nr=12

Aug 21 07:10:51.260 gmt: ISDN BR0/1/0 Q921: User TX -> RRf sapi=0 tei=101 nr=10

Aug 21 07:10:51.724 gmt: ISDN BR0/1/0 Q921: User RX <- DISCp sapi=0 tei=101

Aug 21 07:10:51.724 gmt: %ISDN-6-LAYER2DOWN: Layer 2 for Interface BR0/1/0, TEI 101 changed to down

Aug 21 07:10:51.728 gmt: ISDN BR0/1/0 Q921: User TX -> UAf sapi=0 tei=101

Aug 21 07:10:51.732 gmt: ISDN BR0/1/0 Q931: Ux_DLRelInd: DL_REL_IND received from L2

Any advice will be appreciated...

maanav007 Fri, 08/24/2007 - 00:02

Hi , Some times it happens due to signaling issue at provider end .This is usually due to a D-channel error. Pls chk it

smothuku Fri, 08/24/2007 - 00:08

Hi Dany ,

Please check the voltage you are getting in isdn line using multimeter...

On RJ 45 , connect multimeter to port 4 and 5 and see the output must be in between 96 to 102V.

If you are not getting the volatge in isdn line callup telco..

sometimes TEI_assigned state will go off after restarting the NT Box.

Cheers :)


dany.datacraft Sat, 08/25/2007 - 04:08

Hi Satish,

Thanks for the input (3 pts for u). Something that I would check later, if upgrading IOS doesn't solve this problem.

TAC identified a bug CSCsb10564. We are scheduling to upgrade within these two weeks.

Best regards,



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